Electric-circuit breaker.



' No. 840,614. PATENTED JAN. 8, 1907;

s. B. PREIBERG. ELECTRIC CIRCUIT BREAKER.

' APPLICATION FlLED DBO. 2 1904. v

2 SHEETS-SHEBT 1.

No. 840,614. PATENTED JAN. 8, 1907.

S. B. PRBIBERG. ELECTRIC CIRCUIT BREAKER.

APPLICATION FILED DEC. 28, 1904.

2 SHEETS-SHEET 2.

L g- =7 (C 54 5 2d 4 J] o 5 at 5 7 n-u: NURRIS PETERS cu., wnsmucrou, u!c UNITED sTA'frns PATENT OFFICE.

Specification of Letters Patent.

Patented Jan. 8, 1907.

Application filed December 28. 1904;. Serial No. 238,596.

To (tZZ whom it may concern:

Be it known that I, STANLEY B. FREIBERG, a citizen of the United States,residing at Cincinnati, in the county of Hamilton and State of Ohio,have invented certain new and useful Improvements in Electric -,CircuitBreakers, of which the following is a specification.

My invention relates to circuit-breakers, and has for its object theproviding of a circuit-breaker especially adapted for light work and isintended to take the place of fuses in house-wiring and the inventionconsists in providing the circuit, preferably the positive and negativeconductors or wires thereof heretofore provided with fuses, with a pairof circuit-breakers so arranged that upon the occurrence of abnormalcurrent in the circuit one or the other or both of the circuit-breakerswill automatically disconnect for breaking the circuit, thecircuitbreakers being so arranged, as hereinafter described, that uponthe occurrence of abnormal current the same will open for disconnectingthe circuit to which they may be connected, and thus prevent seriousaccident and fire.

My invention consists, further, in providing a circuit-breaker havingmetallic releasable contacts and also non-metallic releasable contacts,one of said non-metallic contacts secured directly to thereleasing-blade and so constructed and arranged that upon occurrence ofabnormal current or overload the non-metallic contacts will remain incontact until after the disengagement of the metallic contacts of thecircuit-breaker for preventing burning or welding of the metalliccontacts, and, further, in providing a combined manual and automaticcircuit-breaker operated directly from an armature.

My invention will be further understood from the following description.and claims and from the drawings, in which- Figure 1 is a diagram viewllustrating a circuit in which my improved circuit-breakers are located.Fig. 2 is a front elevatlon of my improved circuit-breakers Fig. 3 is aside elevation of the same, partly broken away. Fig. 4 is a detail inside elevation, showing the relation of the contacts in full lines whenthe blade is in fully-raised position and in dotted lines when the bladeis only partially raised for disengaging the metallic contacts while thenon-metallic contacts are still engaged. Fig. 5 is a detail incross-section on theline a: 00 of Fig. 3, showing thenon-metalliccontacts and manner of mounting the same. Fig. 6 is a detail incross-section on the line i y y of Fig. 3, showing the manner ofpivoting I the blade and coiling the spring therefor. Fig. 7 is a detailin perspective, showing the armature and spring for retracting the same.Fig. 8 is a perspective detail of the armaturespring; and Fig. 9 is adetail in section on the line 2 of Fig. 2', showing the manner ofmounting the electromagnet.

A represents the translator, shown as an incandescent lamp, of whichthere may be any suitable number on the circuit, or the translator mayconsist of a motor or other suitable electrical device.

B is the positive conductor, and O is the In wiring the positive andnegative conductors are in practice usually run side by side, althoughitis obvious that the same may be arranged in other suitable manner. Inthe conductors of a given circuit I place a pair of my improvedcircuit-breakers, as shown at E E, in the respective positive andnegative conductors of the branch circuit, preferably side by side,although it is obvious that the circuit-breakers of a pairmay beconnected in series in either the positiveor negative conductors.

The circuit-breakers of a pair are similarly constructed, and aparticular description of one of the pair will suffice for cl'earness,similar parts of the other being referred to by similarreference-numerals bearing the eXponent prime, C.)

In the circuit breaker there is an electromagn'et 1, having a coil 2 andan armature 3, or a solenoid may be substituted therefor. The winding ofthe electromagnet connects at one end 2 with the binding-post 4, towhich one terminal of the conductor of the circuit is secured. Theelectromagnet is secured to a bracket 5, secured to the baseplate 6 ofthe circuitbreaker, both circuit breakers of the pair being preferablymounted on this base-plate, which may be slate or suitablenon-conducting material. The bracket 5 is U-shaped, having its base takeinto and guided by the walls of a groove 7 in the base-plate, thebracket being secured in place by a screw 8, which takes through anarrow slot 9 in the base-plate, thereby permitting adjustment of thecoil and of the electromagnet toward and from the armature forregulating the capacity of the negative conductor, of the branch circuitD.

breaker, thus permitting the circuitbreaker to be adjusted and set tobreak at a certain current strength:

The armature is pivoted upon pivots 10 10 to a U-plate 11, secured tothe base by a screw 12. The armature is normally retracted from the coilof the electromagnet by a spring 13. This spring is bent reversely uponitself, forming a median loop 14, taking about the screw 12, and eachshank of the spring is bent to form a spiral or loop 16 intermediate ofits length, the outer ends of the spring being preferably connected asshown at 18 and taking under thearmature, forming a cheap, effective,and delicate spring mechanism for retracting the armature. For limitingthe retracting movement of the armature the U-plate 11 has a lug 19. Theupper surface of the armature is provided with a lip 20, adapted toreceive the blade 21. This lip is slightly above the pivotal point ofthe armature and has its contacting face slightly inclined rearwardly,the catch 23 of the blade having its contacting face correspondinglyinclined forwardly in subst antially the are of swing of the armaturefor affording a delicate trip for the armature. The blade is releaseddirectly from the armature, insuring quick action and simpleconstruction.

The blade 21 is pivoted on a rod 24, taking through an aperture in theend of the blade and through apertures in the sides of a U- shapedbracket 25, secured to the base by a screw 26, a conductor 27 connectingthe screw 26 with the. bindingpost 28, to which the other terminal ofthe conductor of the circuit is secured. A dished washer 29 takes aboutthe rod to each side of the bracket 25, nuts 30, shown as elongatedround nuts, taking against the washers for securing the rod in place anddelicately regulating the e'ectrical connection of the blade, the bladebeing thereby resiliently pressed between the sides of the bracket.

A metallic contact for the blade, shown as a U-clip, is secured to thebase by a screw 36. A non-metallic contact 37 is secured di rectly onand moves with the blade, and a non-metallic contact 38 is secured tothe base. These latter contacts are non-metal lie or non-welding and arepreferably carbon. They are preferably pressed toward each other withspring-pressure. Thus the contact 38 is preferably mounted on a spring39, secured to the base by a nut and screw 40. This spring is preferablya leaf-spring having a bulge 41 therein, giving it long life. Thecontact-faces 42 43 of the contacts 37 38 are preferably relativelyinclined, the springpressure urging contact of those faces throughoutthe various positions which those contacts assume while side by side andpermitting sharp breaking of contact when the blade 21 is retractedsufficiently to bring the contact 37 out of reach of the contact 38. Theextreme ends of the contacts 37 38 are abruptly inclined or rounded, asshown at 44 45, so as to permit ready engagement and prevent binding ofthose contacts when the blade is reset. The other end 2 of the windingof the electromagnet connects with the screws 36 40, so that themetallic and nonmetallic contacts on the base connect with the sameterminal of the conductor.

Referring to Fig. 4, it will be noted that when the blade is releasedfor breaking contact the metallic contact is first released while thenon-metallic contacts are still in contact, thereby avoiding arcing atthe metallic contact, the electricity flowing through the non-metalliccontacts for an instant after the metallic contact is released, one ofthe non-metallic contacts being carried directly by the knife to insurepositive action, preventing burning or welding of those metalliccontacts, and consequent injury to the same, and insuring safety andcertainty in the op eration of the device. Normally the circuit isformed through both the metallic and carbon contacts; but upon breakingof the circuit the metallic contacts are first released. The blade 21 isretracted by a spring 51. This spring is bent at its central portion forforming inwardly-projecting stirrup 52, taking about the blade below thecarbon contact 37 and forming shanks 53, taking beyond the pivotal pointof the blade, the tail ends thereof being secured by screws 54 to thebase. The shanks cross each other above the blade, as shown at 55,thereby acting as a stop for preventing the outward movement of theblade beyond the spring. The inner part of the stirrup takes across theinner edge of the blade and the crossing parts of the shanks take acrossthe outer edge of the blade, thereby forming a loop within which theblade is confined, so as to prevent the blade from accidentally swingingback too far, owing to its momentum, when the blade is released from thearmature. Each shank 53 is formed with a helix, loop, or coil 56, takingabout one of the nuts 30 of the rod 24, forming a strong spring,providing quick break of circuit. Between the stirrup 52 and loop 56each shank has an outward bulge for removing the spring from contactwith the carbon 37. In order to prevent wear of the contacting face 23of the blade, the blade being usually of soft metal, such as copper, Iprovide a reinforce face-piece 57 of harder metal, preferably takingabout and riveted to the sides of the blade. The blade is provided witha push-button 58. The armature has an extension 59, on which there is aninsulated push-button 60 for permitting the armature to be withdrawnfrom the blade by hand, making a simple combined manually-operated andautomatic circuit-breaker.

IIO

My invention takes the place of fuses, which are expensive inmaintenance and also dangerous, and also of the ordinary switch,combining the functions of both in one device. My improvedcircuitbreaker is not intended for switchboard use, but rather in branchlines carrying limited current. It has few parts and is of cheap anddurable construction and capable of accurate adjustment for currentstrength, making it especially useful for current-circuits forlow-current strength. It can be cheaply made, so as to be capable ofbeing used in place of fuses, and is more accurate and delicate andsafer than fuse construction, because each circuit-breaker can bedefinitely tested and adjusted for a given current strength, which isnot the case with fuses, the testing of which would destroy the fuse.

During normal current circuit is formed through the circuit-breakers.Upon abnormal current, due to a ground, short circuit, overload, orother cause, the armature of one or both circuit-breakers in the circuitis attracted, thus breaking the circuit, the metallic contacts beingfirst released, for the reason stated. Upon discovery and remedy of thesupposed difficulty with the circuit one of the circuit-breakers isfirst connected. If connection in both has been broken, the blade of themating circuit-breaker is then pushed into contact for closing thismating circuit-breaker. If the difiiculty with the circuit has beenactually found and remedied, both circuit-breakers will now remainclosed; but if there should still be abnormal current, ground, oroverload in the circuit the firstnamed circuit-breaker will instantlyfly open, thus preventing injury to any part of the circuit. There beingat least one of the circuit-breakers from which manual resistance toopening or breaking has been removed when the circuit is finally closedand the circuit-breakers breaking independently, injury and danger areremoved, because the circuit cannot remain closed while there isabnormal current in it.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

1. In an electric-circuit breaker, the corrbination with anelectromagnet having an armature, a support for said arn'iature, and abase, of a spring for nori'nally retracting said arniature, said springhaving a central loop below said armature-support and for ring a pair ofstrands, a screw 12 taking through said armature-support and loop andinto said base for securing said support and spring to said base, eachof said strands having a spiral intermediate of its ends, the ends ofeach of said strands projecting upwardly from one side of said spiraltoward said armature-support and armature respectively, and said strandshaving their outer ends take against said armature for normallyretracting the sad; e, a pivoted blade with contacts therefor,

lIBLIlS normally connecting said blade and arniature, and nteansnormally acting to separate said blade and armature, substantially asdescribed.

2. In an electric-circuit breaker, the combination of a base, a blade,said blade having a pivot, a spring for said blade, said spring having acentral stirrup in which the blade rests at one edge of said blade andforming a pair of strands, said strands being bent across the other edgeof said blade and thereby forming a loop about said blade at saidstirrup for forming a stop against undue retraction of said blade, saidstrands extending from said loop toward the pivot of said blade andbeing coiled substantially coincident with the aXis of said pivot, andnleans for securing the ends of said strands rigidly in position,substantially as described.

3. In an electric-circuit breaker, the combination of a base, a blade,said blade having a pivot, a nietallic contact and a non-metalliccontact spaced apart and secured to said base, a nietallic contact and anon-metallic contact spaced apart and secured to said blade, a springfor the blade, said spring having a central stirrup located between saidmetallic and non-rtetallic contacts on said blade, the inner edge ofsaid blade taking against said stirrup, said spring thereby forming apair of strands, said strands crossing the outer edge of said bladebetween said nietallic contact and said non-oi etallic contact thereonand thereby forming a loop within which said blade is confined, saidstrands spreading from said crossed position outwardly for formingbulges 50 and thereby clearing the non-1r etallic contact on said blade,said strands extending from said bulges toward the pivot of said bladeand being coiled coincident with the pivotal axis of said blade, andiiieans for securing the ends of said strands rigidly in position.

In witness whereof I have hereunto subscribed my name in the presence oftwo subscribing witnesses.

STANLEY B. FREIBERG.

